This research study is designed to find out if increasing the dietary intake of polyunsaturated fats improves concentration, motor skills and cardiovascular responses under stress. These polyunsaturated fats may also change the chemicals in the brain that control these responses. Specifically, these polyunsaturated fats may raise brain levels of neurotransmitters called dopamine and serotonin. Polyunsaturated fats are important for improving the function of both the brain and the heart. People cannot make these polyunsaturated fats and they can only be obtained from the oils that we eat. For three months subjects will take 8 capsules a day that contain either corn oils flavored with fish oils or fish oil that taste a little like corn oils. Subjects will not be told which oils we expect to work better. An initial evaluation will determine if subjects fit the criteria necessary to enter the study. A battery of tests will be conducted twice, once before starting the capsules and again after three months of taking the capsules. These batteries of tests will include an MRI of the head, paper and pencil tests to evaluate changes in mood, and tests of concentration and motor skills and cardiovascular responses under stress. Two lumbar punctures will be performed to collect cerebrospinal fluid so that changes in neurotransmitters can be evaluated. Subjects will be on a no seafood diet to equalize their dietary intake of polyunsaturated fatty acids. Subjects will be expected to complete all parts of this study.